title: BPIFB1 is a lung-specific autoantigen associated with interstitial lung disease.
abstract: Interstitial lung disease (ILD) is a complex and heterogeneous disorder that is often associated with autoimmune syndromes. Despite the connection between ILD and autoimmunity, it remains unclear whether ILD can develop from an autoimmune response that specifically targets the lung parenchyma. We examined a severe form of autoimmune disease, autoimmune polyglandular syndrome type 1 (APS1), and established a strong link between an autoimmune response to the lung-specific protein BPIFB1 (bactericidal/permeability-increasing fold-containing B1) and clinical ILD. Screening of a large cohort of APS1 patients revealed autoantibodies to BPIFB1 in 9.6% of APS1 subjects overall and in 100% of APS1 subjects with ILD. Further investigation of ILD outside the APS1 disorder revealed BPIFB1 autoantibodies present in 14.6% of patients with connective tissue disease-associated ILD and in 12.0% of patients with idiopathic ILD. The animal model for APS1, Aire⁻/⁻ mice, harbors autoantibodies to a similar lung antigen (BPIFB9); these autoantibodies are a marker for ILD. We found that a defect in thymic tolerance was responsible for the production of BPIFB9 autoantibodies and the development of ILD. We also found that immunoreactivity targeting BPIFB1 independent of a defect in Aire also led to ILD, consistent with our discovery of BPIFB1 autoantibodies in non-APS1 patients. Overall, our results demonstrate that autoimmunity targeting the lung-specific antigen BPIFB1 may contribute to the pathogenesis of ILD in patients with APS1 and in subsets of patients with non-APS1 ILD, demonstrating the role of lung-specific autoimmunity in the genesis of ILD.
authors.affiliation: Division of Pulmonary and Critical Care, Department of Medicine, University of California, San Francisco, San Francisco, CA 94143, USA.
authors.forename: Anthony K
authors.initials: AK
authors.lastname: Shum
authors.forename: Mohammad
authors.initials: M
authors.lastname: Alimohammadi
authors.forename: Catherine L
authors.initials: CL
authors.lastname: Tan
authors.forename: Mickie H
authors.initials: MH
authors.lastname: Cheng
authors.forename: Todd C
authors.initials: TC
authors.lastname: Metzger
authors.forename: Christopher S
authors.initials: CS
authors.lastname: Law
authors.forename: Wint
authors.initials: W
authors.lastname: Lwin
authors.forename: Jaakko
authors.initials: J
authors.lastname: Perheentupa
authors.forename: Helene
authors.initials: H
authors.lastname: Bour-Jordan
authors.forename: Jean Claude
authors.initials: JC
authors.lastname: Carel
authors.forename: Eystein S
authors.initials: ES
authors.lastname: Husebye
authors.forename: Filippo
authors.initials: F
authors.lastname: De Luca
authors.forename: Christer
authors.initials: C
authors.lastname: Janson
authors.forename: Ravishankar
authors.initials: R
authors.lastname: Sargur
authors.forename: Noémie
authors.initials: N
authors.lastname: Dubois
authors.forename: Merja
authors.initials: M
authors.lastname: Kajosaari
authors.forename: Paul J
authors.initials: PJ
authors.lastname: Wolters
authors.forename: Harold A
authors.initials: HA
authors.lastname: Chapman
authors.forename: Olle
authors.initials: O
authors.lastname: Kämpe
authors.forename: Mark S
authors.initials: MS
authors.lastname: Anderson
mesh_terms: D019264:Adoptive Transfer; D000818:Animals; D001323:Autoantibodies / Q000276:immunology; D001324:Autoantigens / Q000276:immunology* / Q000378:metabolism; D015551:Autoimmunity / Q000276:immunology; D015415:Biomarkers / Q000378:metabolism; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology; D002352:Carrier Proteins / Q000378:metabolism*; D050556:Fatty Acid-Binding Proteins; D005838:Genotype; D006023:Glycoproteins / Q000378:metabolism*; D006801:Humans; D007108:Immune Tolerance / Q000276:immunology; D008168:Lung / Q000276:immunology* / Q000473:pathology*; D017563:Lung Diseases, Interstitial / Q000276:immunology* / Q000473:pathology*; D051379:Mice; D009928:Organ Specificity; D016884:Polyendocrinopathies, Autoimmune / Q000276:immunology; D011506:Proteins / Q000378:metabolism*; D011869:Radioligand Assay; D015203:Reproducibility of Results; D013950:Thymus Gland / Q000276:immunology / Q000637:transplantation; D014157:Transcription Factors / Q000172:deficiency / Q000235:genetics / Q000378:metabolism; D000096927:AIRE Protein
chemical_list: D001323:Autoantibodies; D001324:Autoantigens; D015415:Biomarkers; D002352:Carrier Proteins; D050556:Fatty Acid-Binding Proteins; D006023:Glycoproteins; D011506:Proteins; D014157:Transcription Factors; D000096927:AIRE Protein; C568077:BPIFB1 protein, human; C579352:BPIFB1 protein, mouse